Values, Text, and First Programs: 10 practice questions

Question 1 of 10

Which arithmetic operator always returns a floating-point result?

1. A`/`
2. B`//`
3. C`%`
4. D`**`

Question 2 of 10

What happens when code tries to assign a new character to one indexed position of a string?

1. APython raises `TypeError` because strings are immutable.
2. BPython appends the character to the end of the string.
3. CPython creates a new string and rebinds the original name automatically.
4. DPython replaces the character because strings are mutable.

Question 3 of 10

Which list operation adds one new item at the end?

1. ATake a slice of the entire list.
2. BCall the list's `append()` method.
3. CRead the list's final index.
4. DAssign the list to another variable.

Question 4 of 10

For `word = 'Python'`, what does the slice `word[2:5]` produce?

1. A`'thon'`, because both slice boundaries are included.
2. B`'yth'`, because slicing starts one position before index 2.
3. C`'tho'`, because index 2 is included and index 5 is excluded.
4. D`'ho'`, because both slice boundaries are excluded.

Question 5 of 10

After `rgba = rgb`, what happens if code appends an item through `rgba`?

1. AOnly `rgba` changes because assignment makes a deep copy of the list.
2. BOnly `rgb` changes because the original name owns all mutations.
3. CThe appended item is also visible through `rgb` because both names refer to one list.
4. DNeither list changes because list values are immutable.

Question 6 of 10

How does Python process `a, b = b, a + b` in the introductory Fibonacci program?

1. AIt evaluates both right-hand expressions before performing either assignment.
2. BIt assigns `a` first and then evaluates both right-hand expressions.
3. CIt alternates evaluation and assignment from right to left.
4. DIt assigns `b` first and then evaluates the expression for `a`.

Question 7 of 10

Why can Python display `0.1` even though the stored float is not exactly one tenth?

1. APython stores the exact decimal value but rounds it to binary only during arithmetic.
2. BPython changes the stored value to exact one tenth whenever it is printed.
3. CPython stores every decimal fraction as a finite base-two fraction without approximation.
4. DPython displays a rounded decimal form of the stored binary approximation.

Question 8 of 10

A program needs a string containing `C:\temp\new`, with each backslash preserved, and the value does not end in a backslash. Which literal best satisfies both constraints?

1. AUse the ordinary string `'C:\temp\new'` unchanged.
2. BUse `r'C:\temp\new\'` and remove the last character later.
3. CUse adjacent literals `'C:' '\temp' '\new'` without raw prefixes.
4. DUse the raw string `r'C:\temp\new'`.

Question 9 of 10

A countdown must repeat while a positive integer remains and print each value followed by a comma instead of a newline. Which design meets both requirements?

1. AUse an empty list as the `while` condition and call `print(value, end=' ')` before decreasing it.
2. BUse zero as the `while` condition and call `print(value)` before increasing it.
3. CUse the integer as the `while` condition and write the expression at the prompt without `print()`.
4. DUse the integer as the `while` condition and call `print(value, end=',')` before decreasing it.

Question 10 of 10

A report must show a short decimal result, while a test must tolerate the representation error in `0.1 + 0.1 + 0.1`. Which approach addresses both needs?

1. APrint the full stored fraction and use exact equality because all displayed digits remove the error.
2. BPre-round each `0.1` operand and use exact equality because the inputs then become exact.
3. CFormat the report output and use exact equality because formatting changes the stored value.
4. DFormat the report output to the desired digits and use `math.isclose()` for the comparison.